1. Technical Field
The present invention relates to a semiconductor light emitting device and a method of manufacturing a semiconductor light emitting device.
2. Related Art
In recent years, there have been many proposals to suppress the defects caused by break of elements, particularly in semiconductor devices composed of a Group III nitride semiconductor.
Japanese Laid-Open Patent Publication No. 2008-135785 (JP-A-2008-135785) describes a method of manufacturing a nitride semiconductor device as follows. First, trenches are formed on the surface of a semiconductor wafer, typically using a dicer. Next, break lines are formed by forming a work-affected layer inside the semiconductor wafer below the trenches. The semiconductor wafer is then broken along the break lines. According to JPA-2008-135785, such a method would enable to form highly accurate break lines in narrower and deeper trenches with little variation in working, without degrading accuracy of working typically due to wear of cutting edge of the dicer.
Japanese Laid-Open Patent Publication No. 2010-123869 (JP-A-2010-123869) describes a nitride semiconductor laser device. An n-type cladding layer, an n-type optical guide layer, an active layer, an electron barrier layer, a current blocking layer, a p-type optical guide layer, and a p-type cladding layer are sequentially formed on a substrate. The current blocking layer has a first opening that serves as a current injection portion, and second openings that serve as current blocking portions. First recesses are formed in a region positioned outside the second openings as viewed from the first opening, and the first recesses extend through the electron barrier layer. In addition, second recesses are formed in regions between the first opening and the second openings, and bottoms of the second recesses are positioned above the lower surfaces of the electron barrier layer. In the description, the first recesses are trenches used for element isolation, and the laser chips may be split by scribing. In this way, current leakage ascribable to the first recesses for element isolation may be prevented, and variation in threshold for laser oscillation may be suppressed even if the first recesses have a large depth, according to JP-A-2010-123869.